Valve actuation mechanism



Dec. 16, 1958 c. B. LEACH 2,864,351

VALVE AcTuATIoN MECHANISM Filed Dec. 7, 195e INVENTR ATTORNEY.

United States Patent 'i VALVE AcTUATIoN MECHANISM Clayton B. Leach, Pontiac, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application December 7, 1956, Serial No. 626,925

18 Claims. (Cl. 123-90) The invention relates to mechanism for actuating valves in an internal combustion engine and more particularly to a valve-in-head type engine. In order to place the spark plug in an internal combustion engine very close to the center of the Volume of a combustion chamber and provide for efiicient intake and exhaust valve locations, it is desirable to incline the valves at an angle to the vertical as viewed in a transverse cross section and also incline the valves at an angle to the vertical as viewed in a longitudinal cross section, the center line of the cylinder herein being considered as establishing the Vertical for purposes of description and identification. This angularity reduces the size of the Valve recesses appreciably and makes it practicable to use -larger size valves than would otherwise be possible. When the valves are fully opened, they are well inside the cylinder bore diameter and the flow of intake and exhaust gases is not harmfully shrouded by the cylinders.

One feature of the invention provides such a valve system which is actuated by an independently mounted interchangeable type rocker arm for both intake and exhaust valves and permits the valves to be angularly positioned as described while actuating the valves without introductionof bending moments or scrubbing action in the valve gear train.

Another feature of the invention includes the disposition of the push rods relative to the center line of the cylinder both in transverse and longitudinal planes. By employing an independently mounted rocker arm, the push rod may be obliquely disposed or parallel to the cylinder center line in either a transverse or longitudinal plane, or both, and may be actuated by a valve lifter which is also independently disposed relative to the cylinder. By having this lattiude of disposition, the valves may be more desirably positioned and still be actuated with a minimum of valve gear scrubbing and bending.

When using the conventional rocker arm shaft design it is not possible to actuate the valves in the angular relation desired and still obtain correct valve gear action. The rocker arm shaft would of necessity be located longitudinally in the engine and would not allow rocker arm movement in the plane of the valves, but would introduce scrubbing action between the valve tip and the rocker arms as well as valve cocking and stern wear. The appli-A cation of rocker arm shaft designs to valve mechanisms is limited to valves having a movement 90 degrees to the axis of the rocker arm shaft. By use of independently mounted rocker arms, however, valves having movements at other angles may be employed.

All parts of the valve gear train for any one valve, except the valve lifter, are positioned within a single plane to accomplish this result. The articulation between the lower end of the push rod and the valve lifter has been used andfound to be without deleterious elect. Relatively short push rods of the same length may be used for both the intake and exhaust valves and may therefore also be interchangeable.

Inthe drawing:

2,864,351 Patented nec. 16, 195s Figure 1 is a partial sectional view having parts broken away and showing an internal combustion engine valve train embodying the invention.

Figure 2 is a partial sectional view taken along arrows 2 2 of Figure 1 with parts broken away.

While the internal combustion engine shown is of the in-line single bank type, the invention s equally applicable to other types of engines in which intake and exhaust valves are actuated through mechanical linkage. The portion of the engine `shown includes an engine block 10 and a cylinder head 12 with a camshaft 14 rotatably mounted in the engine block. The engine block and the cylinder head form a combustion chamber 16 above a piston 18 which is positioned within a cylinder 20 formed within the engine block. While only one cylinder is shown, it is obvious that the engine may be provided with additional cylinders. The combustion chamber 16 has an intake valve 22 and an exhaust valve 24 extending therein to provide for introduction of the fuel and air mixture into the combustion chamber and for exhaust of the burned gases from the chamber after combustion takes place. Although the cylinder is provided with both valves, only the intake valve linkage will be described in detail since each of the valves may be actuated by a similar linkage. The valve 22 extends through valve guide 26 and is provided with valve springs 28vand 30. A ball pivot type rocker arm 32 is in engagement with the valve stem tip and is pivotally mounted on a stud 34 which is secured to the cylinder head 12. Rocker arm 32 is actuated by push rod 36 which extends through a push rod guide 38 formed within the cylinder head. The push rod terminates in engagement with the valve lifter 40. Camshaft 14 actuates valvelifter 40 in the proper sequential order to open and close valve 22, as is well known in the art. v

Valve stem 42 of valve 22 and push rod 36 are located within the same plane 5t) as are the rocker arm contact points 44 and 46 and the rocker arm stud 34 with its ball pivot 4S. The plane containing these elements may extend transversely of the engine block and may be disposer at an oblique angle relative toa vertical plane 52. As is seen in Figure 2, the valve stem 54 of exhaust valve 24 is in the same plane 56 with its push rod 58. Plane 56 may also be disposed at an oblique angle relative to a vertical plane 60 and is angled in the opposite direction from the vertical relative to plane 50. The hydraulic valve lifter 40 is not required to be in the same plane as the remainder of the valve gear train but may be vertically or otherwise disposed.

Valves 22 and 24 are also preferably located in the same longitudinally extending plane 62 which also forms an oblique angle with a longitudinally extending vertical plane 64 in order to position the valves angularly within combustion chamber 16.

The use of the ball pivot type rocker arm makes possible l the placement of the valves in planes 50 and 56. Should la conventional rocker arm shaft be used, the valves could exhaust valves at the same relative angles between planes 50 and 52 and 56 and 6i) as well as planes 62 and 64, the same rocker arms 32 may be interchangeably used with either valve, thus simplifying parts manufacture. This arrangement also permits the use of a single type i push rod 36 which may be interchangeable in either valve gear train.

Push rods 36 and 58, while shown in Figure 1 as being non-parallel to cylinder 20 and extending upwardly and inwardly relative thereto, may be easilydisposed parallel to the cylinder or` extending upwardly and outwardly from the cylinder. The disposition desired depends, among other considerations, upon the positions of the valves relative to the combustion chamber.` The valves, or either of them, may be located in the cylinder head on the side nearer the push rods, in which case the rod or rods would extend outwardly from the cylinder. If one valve were mounted. to extend into either side of the combustion chamber, one push rod would angle inwardly and toward cylinder and the other outwardly and away from it. The pivot 48 for each rocker arm may be conveniently located by positioning boss 66 wherever desired and either pressing or threading stud 34 into the boss to secure the pivot in place. These possible arrangements are examples illustrating the versatility available in valve gear trains embodying the invention, and are not to be considered as limiting the invention to these speciiic arrangements.

By placing the intake and exhaust valves at an angle relative to a vertical longitudinal plane as well as at an angle relative to a vertical transverse plane, larger intake and exhaust valves may be provided and simplication of combustion chamber manufacturing techniques is obtained. This is especially true when a spherical segment combustion chamber is used and the valves are so positioned in the transverse and/or longitudinal planes that the extended valve center lines intersect or nearly intersect the center line of the spherical radius which defines the combustion chamber. This disposition reduces the machined recesses required to provide flat valve seat surfaces.

What is claimed is:

l. In an internal combustion engine having a cylinder with a piston disposed therein and a cylinder head cooperating with said cylinder and piston to form a cornbustion chamber, an intake valve and an exhaust valve for said chamber, each of said valves having an actuating linkage including a rocker arm and a push rod, each of said linkages being disposed in a plane passing through its respective valve, said planes being disposed oppositely and angularly from the center line of said cylinder, said valves being further disposed in a cornmon plane angularly oiset from said center line.

2. A valve linkage for an internal combustion engine including a push-rod and a rocker arm and a valve a stem, said elements being disposed in a first plane transverse to said engine and angularly offset from a vertical transverse plane, said valve stem further forming an angle with a vertical longitudinal plane passing through said engine.

3. Mechanism for actuating a valve for the combustion chamber of an internal combustion engine, said mechanism including a camshaft and a valve lifter and a push rod and a rocker arm, said camshaft extending longitudinally of said engine, said lifter being adapted to be actuated by said camshaft and positioned substantially perpendicular to said camshaft, said push rod being in engagement with said lifter for actuation thereby, said valve stem and push rod and rocker arm being in a plane extending generally transversely of said engine and at an angle to a line extending vertically of said engine.

4. In a combustion chamber for an internal combustion engine, a valve having a valve stem angularly oiset transversely and longitudinally of said engine, said valve being actuated by a rocker arm and a push rod disposed in a plane passing through said valve stem.

5. A pair of valve movement linkages for an intake valve and an exhaust valve disposed in a combustion chamber, each of said linkages including a rocker arm and a push rod in a plane including only one of said valves, said valves being angularly disposed to mutually perpendicular planes having thel center line of said combustion chamber positioned therein, said valves being angularly disposed to each other in a third plane having both of said valves postioned therein.

6. The mechanism of claim 5 in which the angle deiined by said valves is bisected by a line in said third plane parallel to said center line.

7. In an internal combustion engine, mechanism including a plurality of combustion chamber valves, each of said valves `being actuated through a rocker arm and a push rod, each of said rocker arms being independently mounted and positioned in a first plane including a valve and a push rod, each of said first planes being in angular relation to transverse and longitudinal vertical planes passing through said engine.

8. The mechanism of claim 9 in which said valves include adjacent intake and exhaust valves in a common plane, said valves being oppositely and equi-angularly spaced relative to one of said transverse vertical planes passing intermediate said adjacent valves.

9. In an internal combustion engine having a cylinder with a piston disposed therein and a cylinder head cooperating with said cylinder and piston to form a combustion chamber, an intake valve and an exhaust valve for said chamber, each of said valves having an actuating linkage including a rocker arm and a push rod, each of said linkages being disposed in a plane passing through its respective valve, said planes being disposed oppositely and angularly from the center line of said cylinder.

10. In a valve actuation linkage for an internal combustion engine having a cylinder and a camshaft and intake and exhaust valves having valve stems, a valve lifter actuated by said camshaft and a push rod actuated by said lifter, said push rod being angularly disposed relative to said cylinder and said lifter and being adapted to actuate one of said valves, said push rod and the valve stem of said one valve being in a common plane.

11. In a valve gear train for actuating a valve in an internal combustion engine having a combustion chamber and a cylinder formed therein, elements including a valve stem for said valve, an independently and universally mounted rocker arm, a push rod and a lifter for said push rod, said lifter and said push rod being relatively angularly disposed, said other elements being located in a plane common to said push rod, said push rod being angularly disposed to said cylinder in a plane transverse to said engine.

l2. In an internal combustion engine having a cylinder and intake and exhaust valves, a valve lifter and push rod for each of said valves, one of said rods extending upwardly and inwardly relative to said cylinder and the other of said rods extending upwardly and outwardly relative to said cylinder, each of said rods being angularly disposed to a vertical transvese plane passing through said engine.

13. A linkage for actuating a valve for the combustion chamber of an internal combustion engine having a cylinder, said linkage including a lifter and a first member angularly engaged therewith, a second member pivotally engaged with said rst member and mounted for universal movement on said engine, a third member including said valve engaged with said second member opposite said iirst member, and means for actuating said lifter whereby said valve is moved, said rst and second and third members being in a common plane, said rst member being angularly disposed to said cylinder.

14. A valve linkage for an internal combustion engine including a push-rod and a rocker arm and a valve stem, said elements being disposed in a first plane transverse to said engine and obliquely oiset from a vertical transverse plane, said valve stem further forming an oblique angle with a vertical longitudinal plane passingv through said engine.

15. In a combustion chamber for an internal combustion engine, a valve having a valve stem obliquely offset transversely and longitudinally of said engine, said valve being actuated by a rocker arm and a push rod disposed in a plane passing through said valve stern.

16. In a valve actuation linkage for an internal cornbustion engine having a cylinder and a camshaft and intake and exhaust valves, a valve lifter actuated by said camshaft anda push rod actuated by said lifter, said push rod being obliquely disposed relative to said cylinder and said lifter and being adaptable to actuate one of said valves.

17. In a valve gear train for actuating a valve in an internal combustion engine having a combustion charnber and a cylinder formed therein, elements including a valve stem for said valve, an independently and uni versally mounted rocker arm, a push rod and a lifter for said push rod, said lifter and said push rod being relatively obliquely disposed, said other elements being located in a plane common to said push rod, said push rod being obliquely disposed to said cylinder in a plane transverse to said engine.

1S. A linkage for actuating a valve for the combustion chamber of an internal combustion engine having a cylinder, said linkage including a lifter and a first member obliquely engaged therewith, a second member pivotally engaged with said rst member and mounted for universal movement on said engine, a third mem-' References Cited in the tile of this patent UNITED STATES PATENTS 2,421,510 Leek et al. lune 3, 1947 FOREIGN PATENTS 226,442 Great Britain Dec. 24, 1924 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No? 2,86A35l December l, 1.958

Clayton B Leach It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column l, line 8,v for "lattiude" read latitude mg; column 2, linee O and 4l, for "disposer" read disposed m; column A., line 14, for

the claim reference numeral "9" read u '7 Signed and sealed this 3rd day of November 1959.,

(SEAL) Attest:

KARL Ho AXLNE Attesting Officer ROBERT C. WATSON Commissioner of Patents 

